|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 1.15 |
| 1987 | | .70 |
| 1988 | | .70 |
| 1989 | | .58 |
| 1990 | | .58 |
| 1991 | | .73 |
| 1992 | | 1.17 |
| 1993 | | 1.17 |
| 1994 | | 1.17 |
| 1995 | | 1.49 |
| 1996 | | 1.71 |
| 1997 | | 1.81 |
| 1998 | | 1.88 |
| 1999 | | 1.88 |
| 2000 | | 2.00 |
| 2001 | | 2.02 |
| 2002 | | 2.03 |
| 2003 | | 2.01 |
| 2004 | | 2.26 |
| 2005 | | 2.03 |
| 2006 | | 2.34 |
| 2007 | | 2.34 |
| 2008 | | 2.34 |
| 2009 | | 2.63 |
| 2010 | | 2.60 |
|
|